PROJECT SUMMARY (See instructions); PROJECT 2: ATTENTION AND DUAL-TASK INTERFERENCE We continue to use a translational behavioral science strategy to bring paradigms with greater analytic power to the study of attention in schizophrenia. The collaboration between Dr. Pashler of UCSD and clinical researchers Drs. Nuechterlein and Subotnik of UCLA has yielded strong evidence in favor of specific models of structural processing bottlenecks in divided attention in schizophrenia. Beyond this, sites of marked structural processing bottlenecks in schizophrenia have been isolated in response selection processes and response production processes. Thus, while perceptual encoding proceeds normally without causing dual-task interference in schizophrenia patients, response selection processes and response production (motoric) processes in one task markedly interfere with doing another task. While many aspects of dual-task interference are abnormal across phases of illness, some component of an abnormally severe processing bottleneck tend to progress in severity from prodromal to later phases of schizophrenia. Motoric interference also predicts later work functioning independently from memory and social cognition deficits, suggesting that it has a distinctive role. In the next phase ofthis project, several new steps are proposed. First, to integrate findings in the memory project with the findings ofthis attention project, we will examine whether declarative memory processes interfere with other simultaneous processing in a way that involves a particularly severe structural processing bottleneck in schizophrenia. Second, we will extend the findings ofthis project to situations that involve motivated decisions with hedonic consequences, rather than only simple pre-designated response selections. Third, we will examine further whether the contribution of motor processes to attentional dysfunction and functional outcome is distinct from the contribution of memory processes. Finally, we will examine the extent to which indicators of particular processing bottlenecks in schizophrenia serve as contributors to functional capacity and through it contribute to everyday functional level.